1. Field of the Invention
The present invention is generally concerned with services made available to users of a telephone network by a server connected to said telephone network.
2. Description of the Prior Art
Telephone services are provided by a server external to the central offices of the telephone network and connected to the network via ISDN (Integrated Services Digital Network) interfaces. Services already offered to digital users and, in some cases, to analog users by the ISDN, for example call forwarding, calling line identification presentation, call filtering, ringback, etc., can be provided differently by forwarding calls to a server capable of completing connections between user terminals. A method of the above kind, like that described in the aforementioned patent application, has the advantage of being easily applicable to all types of digital or analog user terminal.
The present invention is more particularly concerned with the use by the same user of a service utilizing a server external to the network and the complementary ISDN calling line identification presentation service, known as the "CLIP service", utilizing CCITT No. 7 type signalling.
The prior art does not provide any method for simultaneously offering to a user the "ringback" service, for example, employing a server external to the central offices of the telephone network and completing connections, and the "CLIP" service. When a calling user terminal sets up a call to a called user terminal having a screen and subscribing to the "CLIP" service, via a server, i.e. at the server by joining a call between the calling terminal and the server to a call between the server and the called terminal, the number shown on the screen of the called terminal is that of the server and not that of the calling terminal.